New Zealand's most vulnerable children are bearing the brunt of the Government's punitive sanctions against beneficiaries, says Child Poverty Action Group.

Figures obtained by the lobby group under the Official Information Act show since the Government's first round of welfare reforms were introduced in July 2010, 377 beneficiaries with dependent children faced sanctions on their benefits.

Changes under the Future Focus programme required people to reapply for the unemployment benefit after one year, solo parents with children over six to be work-tested and sickness beneficiaries assessed. It introduced a graduated sanction regime which cut benefits by 50 per cent for a first work test failure and 100 per cent for ongoing failure.

A year after the changes, 12,500 people had their unemployment benefits cancelled, saving the Government $17 million, and a further 13,000 went off the domestic purposes benefit.

A breakdown of the figures from Work and Income show that from July 2010 until August this year, 234 solo parents had their benefits cut, along with 129 on the unemployment benefit who had dependent children. A further eight on unemployment benefit training and seven on the sickness benefit with dependent children also faced sanctions.

In 84 cases the youngest child in the family was younger than five and in 63 cases the benefit cut lasted more than four weeks.

"These children almost certainly lead very impoverished lives already. We know poverty can have life-long consequences on children's health, education and well-being."

The Government had failed to consider the needs of vulnerable children in its "ideological zeal for work at any cost", he said.

"In a period of high unemployment and rising costs this amounts to state neglect."

It is estimated there are 270,000 New Zealand children living in poverty.

The second tranche of the Government's reforms came into effect this year and include ensuring sole parents with children five and older are available for part-time work, sole parents with children 14 and older are available for full-time work and those who have another child while on a benefit are available for work after one year.

New benefit categories such as a new job-seeker benefit will be introduced next July.